Techniques for camera framing and camera steering face a number of technical challenges in the broadcast industries. For example, sports broadcasters want to ensure that relevant action is presented in a timely and appropriate manner to viewers. The relevant action typically relates to a number of primary targets such as players or the like. The challenge of presenting appropriate action can become more difficult if a broadcaster wants to include other (secondary) targets without sacrificing coverage of the relevant action. The challenge has grown as virtual cameras become increasingly common. Determining whether a secondary target is in a field of view of a virtual camera whose parameters can be dynamically set poses a number of difficulties in comparison to using a fixed physical camera.
In the broadcasting industry for example, advertisements provide a considerable amount of revenue. This is often the case in sports broadcasting where companies negotiate deals with broadcasters and rights holders to have signage, graphics, and logos positioned on and around a playing field (either positioned physically, or virtually). In return, the signs, graphics, and logos, collectively referred to as advertisements, are exposed to a wider audience of viewers. However, the effectiveness of each advertisement is dependent on whether the advertisement is included in video or images captured and broadcasted by the broadcast cameras. The advertisements are examples of secondary targets. Other examples of secondary targets may relate to providing a particular experience for a viewer, for example showing a particular area such as a goal area, a feature of background scenery, a players' bench and the like. Secondary targets may also relate to identifying a location, for example including marker or a particular feature of reference. The broadcast cameras are typically controlled by individuals.
The individuals controlling the broadcast cameras are camera operators employed by the broadcaster. The role of the camera operators is to provide footage which clearly communicates the events of the game. While a camera operator could be directed to change the field of view of their camera towards an advertisement, the camera operator's primary directive is to capture footage of the events of the game. Whether or not an advertisement is included in the field of view is incidental.
As internet bandwidth increase and the capabilities of providing virtual cameras into broadcast environments such as a playing field grow, that the role of the camera operator is expected to shift towards the home viewer in the desire to provide each viewer a personal perspective. With a home viewer controlling a personal camera perspective, broadcasters will have less control over the exposure of the viewers to advertisement in the environment.
It is important for broadcasters that advertisements be in the field of view of the broadcast cameras. However, depending on the events of the game, and the location of the events in relation to the placement of the adverts, it is typically incidental if the person operating the camera perspective also includes an advertisement in the field of view of the camera.
Some methods to increase the likelihood of advertisements being the camera's field of view are known. One known method comprises virtually augmenting advert graphics onto a playing surface of a sports broadcast. The method uses a chroma key technique to create an illusion that the graphic is painted onto the surface. The method provides broadcasters the opportunity to easily swap advertisements while also positioning the advertisements in locations where there is high likely hood of the advertisements being seen. The method can be useful because the cameras which use the method are largely fixed in space, enabling only pan, tilt, roll and zoom adjustment capabilities. With the adjustment constraints, one could ascertain the regions which will experience high level of coverage. In camera systems that allow a greater degree of freedom (freedom in the X, Y, and Z axes in addition to pan, tilt, roll, and zoom) there is less certainty about which surfaces will experience high levels of coverage as more possible perspectives become viable.
Another known method comprises dynamically inserting an advertisement into the frames of a moving image. In particular, the method determines a series of frames where an advertising region is included. Based on the maximum available size for an advertising region, a piece of advertisement is selected and inserted into the region. The method also allows broadcasters to swap the advertisements which also appear in a scene. Apart from the benefit of not having to permanently position adverts, the method provides different advertisements the opportunity to be positioned in a finite amount of regions. However, similarly to the method described above, in a camera system which allows for a greater amount of degrees of freedom, then there is a greater chance that the camera field of view will not include an advertising region. The method can therefore result in no advertisement being shown.